In MySQL 5.6 we introduced a huge improvement in the way that
index and table statistics are gathered by InnoDB and
subsequently used by the Optimizer during query optimization:
Persistent Statistics. Some aspects of the way
that Persistent Statistics work could be improved
further though, and we’d really like your input on that.

How much to sample?

The statistics are gathered by picking some pages semi-randomly,
analyzing …

When analyzing response time, or latency, you need much more
information than an average provides. The average, commonly the
arithmetic mean, shows the index of central tendency. But, as I
found in earlier posts, the tendency is often not central, but
may be skewed by outliers, or split by multiple modes. How often these factors occur …

It is a truth universally acknowledged that the average is the
index of central tendency. But what if the tendency isn’t
central?

I’ve worked many performance issues where the latency or response
time was multimodal, and higher-latency modes turned out to be
the cause of the problem. Their existence isn’t shown by the
average – the arithmetic mean; it could only be seen by examining
the distribution as a histogram, density plot, …

InnoDB improvements in MySQL 5.6 are well known. One of the key
reasons to upgrade to MySQL 5.6 for most users is to get the
benefits of improved performance, scalability, new monitoring
features and fulltext indexes support in InnoDB.

Is there anything to double check before assuming that InnoDB in
MySQL 5.6 is just better than any older version for any practical
purposes? Let's review known public InnoDB-specific bug reports.
Here is my "Top 10" list, as of MySQL 5.6.12, starting with most
recent reports:

Even in times of a growing market of specialized NoSQL databases,
the relevance of traditional RDBMS doesn't decline. Especially
when it comes to the calculation of aggregates based on complex
data sets that can not be processed as a batch like
Map&Reduce. MySQL is already bringing in a handful of
aggregate functions that can be useful for a statistical
analysis. The best known of this type are certainly:

More stats for your consumption! Here are the latest additions to
the environment overview reporting features. On the overview
page, as of revision 238, you will find the following data for
your servers. Update your revision now using ’svn update’ to get
the new features or wait until the next formal release if you are
[...]

OpenSQLCamp was a huge success! I took videos of
most of the sessions (we only had 3 video cameras, and 4 rooms,
and 2 sessions were not recorded). Unfortunately, I was busy
doing administrative stuff for opensqlcamp for the opening
keynote and first 15 minutes of the session organizing, and when
I got to the planning board, it was already full….so I was not
able to give a session.

OpenSQLCamp was a huge success! Not many folks
have blogged about what they learned there….if you missed it, all
is not lost. We did take videos of most of the sessions (we only
had 3 video cameras, and 4 rooms, and 2 sessions were not
recorded).

All the videos have been processed, and I am working on uploading
them to YouTube and filling in details for the video
descriptions. Not all the videos are up right now….right now all
the lightning talks are up.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.